It estimates a solution for instances of the traveling salesman problem which have categories, ie, we have two categories of cities and we want to hit each category once.
This code is used in runr, a Facebook Summer of Hack NY 2012 hackathon entry by Russ Frank, Steve Lu and Wayne Sun.
Check out the finished hack here.
var nnn = require('nearest-category');
// List of locations
var locations = [
{name: "Laundry Locker", lat: "37.770888", lon: "-122.422287", category: "laundry"},
{name: "Jack's Laundry", lat: "37.765973", lon: "-122.433382", category: "laundry"},
{name: "Guerrero Laundry", lat: "37.763255", lon: "-122.424031", category: "laundry"},
{name: "Mikado Sushi", lat: "37.765871", lon: "-122.410711", category: "sushi"},
{name: "Sushi Zone", lat: "37.771403", lon: "-122.423814", category: "sushi"},
{name: "Daimaru Sushi", lat: "37.764596", lon: "-122.431069", category: "sushi"}
];
// List of categories
var categories = ['sushi', 'laundry'];
// Base model. We could solve based on a set of assumptions by setting
// `locations` to some partial trip. `categories` is the list of categories
// we've visited thus far in the model, mapped to true (ie {sushi: true} would
// mean we've visited a sushi place).
var model = {
locations:[{name: "start", lat: "37.771403", lon: "-122.423814", category: false}],
distance: 0,
categories: {}
};
var res = nnn.solve(model, locations, categories);It'll return an array of the best trips we could calulate. Currently it explores 5 iterations inward; this may eventually be configurable.
One trip is a complete model; see the above for an idea of what models
look like.
Here's some sample output:
[
{
"locations": [
{
"name": "start",
"lat": "37.771403",
"lon": "-122.423814",
"category": false
},
{
"lat": "37.771403",
"lon": "-122.423814",
"name": "Sushi Zone",
"category": "sushi",
"distances": {
"37.771403|-122.423814": 0,
"37.764596|-122.431069": 0.614993836167184
}
},
{
"name": "Laundry Locker",
"lat": "37.770888",
"lon": "-122.422287",
"category": "laundry",
"distances": {
"37.771403|-122.423814": 0.09067216308196652,
"37.764596|-122.431069": 0.6473538616708492,
"37.765871|-122.410711": 0.721046744534902,
"37.763255|-122.424031": 0.5359231831388118,
"37.765973|-122.433382": 0.694652117158943
}
}
],
"distance": 0.09067216308196652,
"categories": {
"sushi": true,
"laundry": true
}
},
{
"locations": [
{
"name": "start",
"lat": "37.771403",
"lon": "-122.423814",
"category": false
},
{
"lat": "37.771403",
"lon": "-122.423814",
"name": "Sushi Zone",
"category": "sushi",
"distances": {
"37.771403|-122.423814": 0,
"37.764596|-122.431069": 0.614993836167184
}
},
{
"name": "Guerrero Laundry",
"lat": "37.763255",
"lon": "-122.424031",
"category": "laundry",
"distances": {
"37.771403|-122.423814": 0.5630977415498589,
"37.764596|-122.431069": 0.395431827865439,
"37.765871|-122.410711": 0.7496633627304206
}
}
],
"distance": 0.5630977415498589,
"categories": {
"sushi": true,
"laundry": true
}
},
{
"locations": [
{
"name": "start",
"lat": "37.771403",
"lon": "-122.423814",
"category": false
},
{
"lat": "37.771403",
"lon": "-122.423814",
"name": "Sushi Zone",
"category": "sushi",
"distances": {
"37.771403|-122.423814": 0,
"37.764596|-122.431069": 0.614993836167184
}
},
{
"name": "Jack's Laundry",
"lat": "37.765973",
"lon": "-122.433382",
"category": "laundry",
"distances": {
"37.771403|-122.423814": 0.6433111817661769,
"37.764596|-122.431069": 0.15815438129689982,
"37.765871|-122.410711": 1.2383026155014534,
"37.763255|-122.424031": 0.5441880046398461
}
}
],
"distance": 0.6433111817661769,
"categories": {
"sushi": true,
"laundry": true
}
},
{
"locations": [
{
"name": "start",
"lat": "37.771403",
"lon": "-122.423814",
"category": false
},
{
"lat": "37.764596",
"lon": "-122.431069",
"name": "Daimaru Sushi",
"category": "sushi",
"distances": {
"37.771403|-122.423814": 0.614993836167184
}
},
{
"name": "Jack's Laundry",
"lat": "37.765973",
"lon": "-122.433382",
"category": "laundry",
"distances": {
"37.771403|-122.423814": 0.6433111817661769,
"37.764596|-122.431069": 0.15815438129689982,
"37.765871|-122.410711": 1.2383026155014534,
"37.763255|-122.424031": 0.5441880046398461
}
}
],
"distance": 0.7731482174640838,
"categories": {
"sushi": true,
"laundry": true
}
},
{
"locations": [
{
"name": "start",
"lat": "37.771403",
"lon": "-122.423814",
"category": false
},
{
"lat": "37.764596",
"lon": "-122.431069",
"name": "Daimaru Sushi",
"category": "sushi",
"distances": {
"37.771403|-122.423814": 0.614993836167184
}
},
{
"name": "Guerrero Laundry",
"lat": "37.763255",
"lon": "-122.424031",
"category": "laundry",
"distances": {
"37.771403|-122.423814": 0.5630977415498589,
"37.764596|-122.431069": 0.395431827865439,
"37.765871|-122.410711": 0.7496633627304206
}
}
],
"distance": 1.010425664032623,
"categories": {
"sushi": true,
"laundry": true
}
}
]Tests are written in mocha. To test, type
$ npm testMIT